Cummins Marine Diesel Repower Specialists Forums Instrumentation & Electronics Chasing down jumpy gauges – protecting connections.

  • This topic has 5 replies, 3 voices, and was last updated 5 years ago by Paul.
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  • #37341

    Paul
    Participant
    Vessel Name: Changes in L'Attitudes
    Engines: Twin Cummins 330HP 6BTA 5.9-M-3
    Location: Merritt Island, FL
    Country: USA

    1999 Cummings 6BTA 5.9 M-3. I’m chasing oil gauge issues on both engines. At low RPMs (<1,000) no issues, all gauges indicate rock steady. When pushing up to say 2,000 one or both gauges will start to swing erratically, and eventually fall to zero. This typically leads to an engine alarm in a few minutes (though not always – not sure why). Jogging the throttles to bring RPMs up and down tends to bring the gauges off the zero, but again they swing erratically.

    Going to start with the easy stuff … connections at the gauges and on the wiring harness/grounds. Is there something I can put on/coat the connections after I check/clean them off a bit to help ensure the connections stay good for as long as possible?

    If the connections aren’t the issues, I’ll move on to testing the gauges (though I doubt that’s the problem since the engines often times will alarm, indicating it’s the signal coming to the helm) and eventually the sensor/senders.

Viewing 5 replies - 1 through 5 (of 5 total)
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  • #37859

    Paul
    Participant
    Vessel Name: Changes in L'Attitudes
    Engines: Twin Cummins 330HP 6BTA 5.9-M-3
    Location: Merritt Island, FL
    Country: USA

    Looks like a plan

    WD-40 and brushes followed by white Li grease (I’ve got a tube of that I use on my garage door). I’ll let you know how it goes.

    #37850

    Tony Athens
    Moderator
    Vessel Name: Local Banks
    Engines: QSB 6.7 550 HP
    Location: Oxnard, CA
    Country: USA

    Coating low voltages electrical connections:

    Use any petroleum based dielectric–And for low voltage DC connections, the list is long.. Anything from plain Vaseline as Bill D mentioned, to specialty products like WD-40, Corrosion-X, etc, to my favorite, common WHITE Lithium grease.. For cleaning I prefer a tooth brush and WD-40.

    My SOP for over 50 years– Nothing goes together without something along those lines..I learned that in my off road Motor Cycle days mud racing..

    Why not “silicone” dielectrics? I don’t like them because if they get on anything else, they are hard to remove, ones tends to be be stingy using them (you always need copious amount) , they are expensive and never handy like common grease is.

    Tony

    #37848

    Paul
    Participant
    Vessel Name: Changes in L'Attitudes
    Engines: Twin Cummins 330HP 6BTA 5.9-M-3
    Location: Merritt Island, FL
    Country: USA

    Protecting ground path connections after cleaning.

    Gonna attack the ground path connections this week (hopefully) and will probably go with the old standard disconnect then clean with baking soda/water & wire brush method. After getting everything all pretty is petroleum jelly the best thing to coat the connections after they’re made back up?

    #37379

    Paul
    Participant
    Vessel Name: Changes in L'Attitudes
    Engines: Twin Cummins 330HP 6BTA 5.9-M-3
    Location: Merritt Island, FL
    Country: USA

    Grounds are a good place to start.

    Thanks Corey … No air pre-heaters. No voltage fluctuating when the oil pressure gauges are going wacky. In fact – fuel, temp and voltage are all pretty steady. Tachs tend to act up from time to time.

    #37365

    Corey Schmidt
    Forum Moderator
    Vessel Name: Rebel Belle
    Engines: Cummins
    Location: Oxnard, CA
    Country: USA

    If the issues are persisting on BOTH side, then it sounds like you have a GROUNDING issue either at the sending units are somewhere else…

    Check, clean, and re-tighten ALL of your grounds…

    Do you have the air pre-heaters on your engines?

    Do you notice voltage fluctuating when the gauges are acting erratic?

Viewing 5 replies - 1 through 5 (of 5 total)

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